Sanji will go to the roof.
1. hes closer to the scabbards than anyone else barring Luffy. As he was there when this storyline to Kaido and oden began he’ll be there when it ends
2. what he does up there is up to doubt. Will he injure Kaido to the point of Oden and what Zoro will probably do? Doubtful.
3. That’s not Sanji his power and character isn’t about damaging it’s about protecting so he’ll probably do some damage to Kaido but his big moment won’t be him damaging Kaido it’ll probably be parrying a super attack from big mom since his new power up, raid suit, is a defensive one and is related to big mom more than Kaido.